Google’s CFO, Patrick Pichette, recently reported that in the first quarter of 2011 over 600,000 people had applied for jobs @ Google, which is why I am humbled to recently have had the opportunity to interview for a Product Manager role with the Google team in Zürich.  This post captures a few random thoughts on the experience which hopefully may be of use to other folks going through the process.  But before diving in, a bit of housekeeping…

Why are you interviewing?

I think it’s important to start-off with the fact that I love my job.  I get to work with absolutely brilliant folks who are researching the forefront of ridiculously cool digital technologies (you can get a glimpse here: http://www.cngl.ie/researchpub.html).  I don’t need a new job nor do I necessarily want a new job which ironically enough is the perfect environment to consider new jobs because the bar is set so ridiculously high there is a low probability of taking a position for the wrong reasons…after all desperation is the codependent enabler of suboptimal decision-making!

Aren’t you worried your current employer will find out you are interviewing?

I have tried to be transparent about interviewing right from the get-go.  Quite a few  colleagues called my transparency “bold” and even Penelope Trunk says interviewing is one of the three times you should lie @ work!  However despite what Penelope suggests, I think radical transparency is an increasingly important quality…especially as social media continues to erode the walls between work life & private life. Suppose it’s time for employers to just get used to it…kind of like how I got used to that whole all-knowing big brother, Google knows me better than myself thing! Cheers to progress!

Did you get the job?

Too early to tell…but with 600,000 applications I’m pretty sure there were folks much smarter than me who were interviewing!  

UPDATE: Still too early to tell…but they are bringing me back for another round of interviews.  

Enough already…tell me about the process!

Recruiter Screening:

It all started a few weeks ago with a phone screening with the recruiter.  Was actually a fairly short 20 min. conversation with a few questions about my background, “why” Google and an explanation of their recruiting process.  

Product Manager Screening:

From there I progressed to a 45 min. phone interview with an actual Product Manager. After a few perfunctory questions about my background the format switched to the standard case-based questions you so often read about.  We only had time for two case questions, the first around product strategy and the second around analytics.  

For the product strategy question I was asked how I would design a mobile application to increase literacy among a population of illiterate fisherman somewhere in the South Pacific.  There was a good bit of dialogue between myself and the interviewer as he moved me through the case.  Key points that came up in the discussion included things like the type of interface/UI, prototyping, network, bandwidth & device constraints, information requirements, cultural preferences, etc. 

For the analytical question the interviewer explained I had 8 identical-looking balls, one of which was slightly heavier than the other 7 (all of which weighed the same). Using an old-fashioned balance he asked me to determine the heaviest ball in the least number of weighings (answer here).  After answering his first question we then went back and forth as he asked me to try to identify patterns and a potential formula to calculate the least number of weighings for n=2,3,4,5… balls.  

Ultimately I felt pretty good about my answers to the strategy question and while I didn’t give-up on the analytical question I felt that I should have performed better. Subsequently I was delighted when the following week I received an invitation to participate in the next round of interviews in Zürich.

In-Person Interview x3:

In Zürich I was scheduled for three 45 min. interviews each focusing on a different area:

• Product Development & Design
• Analytical Ability
• Engineering & Technical  

The first two were with Product Managers and the third was with a software engineer. 

During the product development interview I was given three questions.  First I was asked how I would design a cell phone for the 10-15 year old segment of users.  Key themes that I hit on included observational studies, emerging usage trends, novel features (ad-hoc mobile social networks using near-field communications), OS interface, physical design, etc.  For the second question I was asked to provide general commentary on the Android/IOS market dynamics and secondly provide specific recommendations for both Apple & Google.  Finally I was asked what issues I would like to address if I were to build a task management system from scratch.  

For the analytical interview I was again walked through a set of three questions designed to gauge the ability to analyze Fermi problems.  For the first question I was asked to estimate the digital storage requirements for all of the books in Ireland. Ultimately I did come up with a number but there were more interesting discussions around the assumptions I was making, ways to test & verify them and implications of the law of large numbers.  For the second question I was asked to devise a strategy to verify the data quality of a new 3rd party information vendor (think local business YellowPage listings.)  Ultimately I came up with three strategies (the crowd, comparisons with a gold standard and an automated process using speech synthesis/recognition) all of which relied upon a random statistical sampling of zip codes.  

For the final question I was asked how I would increase participation in the authoring process on Wikipedia.  My answer assumed a gaussian distribution of users with a long-tail of active contributors between 2σ-3σ.   I was originally looking at strategies to encourage usage within a band of 1σ around the mean, but as I was working my way through the question I refocused on the band between 1σ and 2σ, with my reasoning being these were folks on the edge that could more easily be encouraged to engage by strategically leveraging some of BJ Foggs frameworks on persuasive computing.  

During the final technical/engineering interview I was given another question very much styled after the one in my phone screen: assuming a person is standing at the bottom of six steps and can go up either one or two steps at a time, how many different ways are there for the person to get to the top?  A relatively straight forward question which I would come to discover most people (including me) attempt to solve using factorial combinatorics.  After arriving at the answer for n=6 stairs I was asked to find the pattern for n=2,3,4,5 and eventual 60 stairs, in which case factorials quickly become cumbersome.  There is an amazingly elegant solution, which I didn’t pick up on, but I was somewhat comforted by the fact that when I got back to the office and presented the question to 3-4 post-doctoral researchers no one else saw it either!  

Overall Thoughts:

Google is in a perpetual state of hiring which I imagine is a logistical nightmare, yet through the whole process the Recruiter and Recruiting Coordinate did a fantastic job keeping me briefed, explaining next steps and getting me to where I needed to be.  

With the Product Manager roles it seems like Google is looking for 3-D intermediaries, folks who, while not necessary an expert in all of the areas, can operate across strategy, design and engineering disciplines.  I get the impression they are looking for classic T-shaped people who have a diverse background and broad skillset.  

I tend to be a lateral thinker, which means my answers can sometimes appear disjointed.  If you are a lateral thinker I think it is worthwhile practicing linear techniques for case interviews, as they will help structure and increase the coherence of your answers as you work through the process.

Finally, perhaps I am weird, but I actually enjoyed the process.  It was a refreshing and thought-provoking change from your standard “what are your top-3 strengths” style interviews. I can’t stress enough the importance of going in and trying to have a bit of fun through the process.  

FYI: Don’t wear a black suit & tie to the interview! The lad that came in shortly after I arrived looked about as out of place as Richard Dawkins at a Discovery Institute strategy session!

Due to the interdisciplinary nature of interviews I think preparing for them is a challenge, however for those inclined here is a list of an additional 25+ Google-style questions I stumbled upon as I was prepping for the interview.  

Google Interview Questions: Product Manager

• How would you boost the GMail subscription base?
• What is the most efficient way to sort a million integers?
• How would you re-position Google’s offerings to counteract competitive threats from Microsoft?
• How many golf balls can fit in a school bus?
• You are shrunk to the height of a nickel and your mass is proportionally reduced so as to maintain your original density. You are then thrown into an empty glass blender. The blades will start moving in 60 seconds. What do you do?
• How much should you charge to wash all the windows in Seattle?
• How would you find out if a machine’s stack grows up or down in memory?
• Explain a database in three sentences to your eight-year-old nephew.
• How many times a day does a clock’s hands overlap?
• You have to get from point A to point B. You don’t know if you can get there. What would you do?
• Imagine you have a closet full of shirts. It’s very hard to find a shirt. So what can you do to organize your shirts for easy retrieval?
• Every man in a village of 100 married couples has cheated on his wife. Every wife in the village instantly knows when a man other than her husband has cheated, but does not know when her own husband has. The village has a law that does not allow for adultery. Any wife who can prove that her husband is unfaithful must kill him that very day. The women of the village would never disobey this law. One day, the queen of the village visits and announces that at least one husband has been unfaithful. What happens?
• In a country in which people only want boys, every family continues to have children until they have a boy. If they have a girl, they have another child. If they have a boy, they stop. What is the proportion of boys to girls in the country?
• If the probability of observing a car in 30 minutes on a highway is 0.95, what is the probability of observing a car in 10 minutes (assuming constant default probability)?
• If you look at a clock and the time is 3:15, what is the angle between the hour and the minute hands? (The answer to this is not zero!)
• Four people need to cross a rickety rope bridge to get back to their camp at night. Unfortunately, they only have one flashlight and it only has enough light left for seventeen minutes. The bridge is too dangerous to cross without a flashlight, and it’s only strong enough to support two people at any given time. Each of the campers walks at a different speed. One can cross the bridge in 1 minute, another in 2 minutes, the third in 5 minutes, and the slow poke takes 10 minutes to cross. How do the campers make it across in 17 minutes?
• You are at a party with a friend and 10 people are present including you and the friend. your friend makes you a wager that for every person you find that has the same birthday as you, you get $1; for every person he finds that does not have the same birthday as you, he gets $2. would you accept the wager?
• How many piano tuners are there in the entire world?
• You have eight balls all of the same size. 7 of them weigh the same, and one of them weighs slightly more. How can you find the ball that is heavier by using a balance and only two weighings?
• You have five pirates, ranked from 5 to 1 in descending order. The top pirate has the right to propose how 100 gold coins should be divided among them. But the others get to vote on his plan, and if fewer than half agree with him, he gets killed. How should he allocate the gold in order to maximize his share but live to enjoy it? (Hint: One pirate ends up with 98 percent of the gold.)
• You are given 2 eggs. You have access to a 100-story building. Eggs can be very hard or very fragile means it may break if dropped from the first floor or may not even break if dropped from 100th floor. Both eggs are identical. You need to figure out the highest floor of a 100-story building an egg can be dropped without breaking. The question is how many drops you need to make. You are allowed to break 2 eggs in the process.
• Describe a technical problem you had and how you solved it.
• How would you design a simple search engine?
• Design an evacuation plan for San Francisco.
• There’s a latency problem in South Africa. Diagnose it.
• What are three long term challenges facing Google?
• Name three non-Google websites that you visit often and like. What do you like about the user interface and design? Choose one of the three sites and comment on what new feature or project you would work on. How would you design it?
• If there is only one elevator in the building, how would you change the design? How about if there are only two elevators in the building?
• How many vacuum’s are made per year in USA?

Related articles

• Google’s unusual job interview question (kottke.org)